St. Louis, MO (KSDK) - U.S. Senator Roy Blunt (R-MO) and U.S. Sen. Claire McCaskill (D-MO), both sent letters to Secretary of the Army John McHugh Thursday, demanding answers to Cold War tests that were conducted in St. Louis in the 1950s and 1960s.

On Monday, the I-Team's Leisa Zigman revealed hundreds of now unclassified documents that exposed how the Army sprayed zinc cadmium sulfide on thousands of unsuspecting St. Louisans.

Sociologist Lisa Martino-Taylor has spent years trying to uncover details of the Army's ultra-secret military experiments. She obtained documents from multiple federal agencies showing that St. Louis was among several cities where the aerosol testing took place.

Sen. Blunt wrote, "The idea that thousands of Missourians were unwillingly exposed to harmful materials in order to determine their health effects is absolutely shocking. It should come as no surprise that these individuals and their families are demanding answers of government officials."

"Given the nature of these experiments, it's not surprising that Missouri citizens still have questions and concerns about what exactly occurred and if there may have been any negative health effects," McCaskill said. "The National Research Council recommended that additional studies should be conducted and it's my goal to find out whether or not they were."

The Army insists the chemical was harmless, but citizens are outraged they were tested and sprayed without their knowledge or consent.

In addition, Robert Alvarez, a former senior policy adviser to the U.S. Secretary of Energy and now a senior scholar at the Institute for Policy Studies, said Thursday, "Dr. Martino-Taylor has reopened a dark chapter of recent history in which the most vulnerable people were put in harm's way without their knowledge. Along with radiation experiments for the nuclear weapons program the callus lack of medical ethics is a tragic hallmark of the Cold War era."

On Thursday, Martino-Taylor released the following statement to NewsChannel 5: "Any real and legitimate investigation will include public comment and participation from former residents in the affected areas. Their voices have not been heard. It would be very inappropriate for government agencies- some of which designed these tests- to conduct an investigation without availing themselves of the first-hand experiences of those residents who were directly affected."

Click here to see Martino-Taylor's research and the unclassified government documents.